Sampling bit for bore-hole machinery



Sept. 12,, 1933. =P.-W. CULSHAW 11,926,033

SAMPLING BIT FOR BORE HOLE MACHINERY Filed April 10, 1930 f/vmswrofi: PETER M Gus/MM Patented Sept. 12, 1933 SAMPLING BET FOR BORE-HQLE lVIACHINERY Application April 10, 1939, Serial No. 443,206, and. in Great Britain April 5, 1929 3 Claims.

This invention is for improvements in or relating to sampling-bits for bore-hole machinery.

Previously in bore-hole apparatus for obtaining samples it has been proposed to use drills of the type known as diamond core drills, in which a hollow cylindrical metal bit is set with diamonds to provide cutting faces. Upon rotation the bit cuts its way with a trepanning action, the core, which is preserved intact as a sample, passing up through the interior of the bit. In this type of drill a constant supply of Water has to be forced down to the cutting face both to carry away the heat generated and to wash up the cuttings. it will be appreciated that the use of diamond core drills is restricted to localities where there is a plentiful supply of water, which condition does not obtain in many of the fields now being opened The object of this invention is to provide an improved bit which may be utilized to obtain cores as samples of the strata pierced, and which bit may also be used without a supply of water to the cutting faces.

To this end the present invention provides a sampling-bit for bore-hole machinery comprising the combination with a rotary cutting tool and a cylindrical shell surrounding said tool,

of locating means at the upper end of the shell to constrain the latter against movement in relation to the tool in axial and radial directions.

In order to remove dirt and borings from the bore-hole it has already been proposed in bits 3 for bore-hole machinery to surround an auger drill with a cylindrical shell, but in that case the shell was loosely mounted on the auger and free to move within limits in relation thereto in directions parallel with and transversely to the auger.

In the sampling-bit according to the present invention, in order to facilitate the withdrawal of the samples from the shell preferably the upper end of the latter is secured to a member which is constrained as aforesaid in relation to the tool but is readily detachable from the tool when required. When the tool is in the form of an auger it may, with advantage, be constituted by a twisted strip of metal.

In order to retain the sample within the shell during the withdrawal of the sampling-bit from the bore-hole the interior of the shell may be provided with spiral flirting. In the preferred construction this spiral flirting is formed by a plurality of spiral incisions in the walls of the shell, the wall of the shell along one or both edges of each incision being turned inwards.

One construction according to this invention will now be described in detail by way of example with reference to the accompanying drawing, in which Fig. l is a section through the shell of a' sampling-bit, providing an external view of the cutting tool, and

Fig. 2 is a part section, showing the bearing of the shell in section, and the shell itself in elevation.

Throughout this description like reference numerals indicate like parts.

The sampling-bit comprises an auger 10 providing the usual peripheral spirals, and the augur is surrounded by a rotatable shell 11. The upper end of the auger is welded to an internally threaded shank 12 while the lower or cutting end is splayed out as at 13 to a diameter slightly in excess of that of the shell 11. The shank 12 is screwed onto a coupling 14 which is itself arranged to be screwed to drill rods of the usual type. The shell 11 is at its upper end welded and also screwed by countersunk-headed screws 16 to a cylindrical member 15 which is rotatable on the coupling 14 aforesaid forming a journal bearing. Above the member 15 is located a brass thrust-washer 1'7 and a steel washer 18, these being locked in position. by a lock nut 19 screwed onto the coupling 14. Thin annular extensions 22 and 23 of the washers 17 and 18 'espectively prevent foreign matter working in between the thrust faces of the thrust bearing above described. The down' ward pull of the shell when the sampling-bit is being withdrawn from the bore-hole is taken by the face 24 of the shank 12.

The shell 11 for a portion of its length is formed with a number of spiral incisions 20, in the form shown the metal of the shell along one edge of each incision being turned inwards as at 21 to form spiral fiutings in the interior of the shell. Obviously, however, the metal at both edges might be turned inwards if desired. The 5 function of these ilutings is to retain the sample during the withdrawal of the bit from the borehole. The operation of the device is as follows. The coupling 14 is attached to the end of a series of drill rods which are rotated and positively fed downwards into the soil. The ends 13 of the auger cut a hole sufficiently large to accommodate the shell 11, the cuttings being packed into the interior of the shell. When the latter is full the drill rods and the sampling-bit are with z.

drawn by hoisting mechanism to the surface, the spiral flutings in the interior of the shell cooperating with the spirals and splayed cutting end of the auger to prevent the cuttings being lost. At the surface the sampling-bit is dismantled and the core contained in the interior of the shell preserved as a sample of the strata which has been pierced in the drilling operations.

While'there is in this application specifically described one form which this invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modifled and embodied in various other forms without departing from its'spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. A sampling-bit for bore-hole machinery comprising the combination with a rotary tool and a cylindrical shell surrounding the tool, of sample retaining means comprising spiral fluting formed on said shell, said spiral fluting being formed by a plurality of spiral incisions in the wall of the shell, the wall of the shell along one or both edges of each incision being turned inwards.

2. A sampling-bit for bore-hole machinery comprising the combination with a rotary auger tool having spirals thereon and a cylindrical shell surrounding the auger tool, of sample retaining means comprising spiral fiuting formed on the shell and cooperating with the spirals of the auger, said spiral fluting being formed by a plurality of spiral incisions in the wall of the shellfthe wall of the shell along one or both edges of each incision being turned inwards.

3. A sampling-bit for bore-hole machinery comprising the combination with a rotary auger tool having spirals thereon and a splayed cutting end and a cylindrical shell surrounding the auger'tool, of sample retaining means comprise ing spiral fluting formed on the shell and cooperating with the spirals and the splayed cut ting end of the auger, said spiral fiuting being formed by a plurality of spiral incisions in the wall of the shell, the wall of the shell along one or both edges of each incision being turned inwards.

PETER WILLIAMS CULSHAW. 

